1,318 → 1,5 |
#ifndef _ASM_X86_ATOMIC_H |
#define _ASM_X86_ATOMIC_H |
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#include <linux/compiler.h> |
#include <linux/types.h> |
//#include <asm/processor.h> |
//#include <asm/alternative.h> |
#include <asm/cmpxchg.h> |
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/* |
* Atomic operations that C can't guarantee us. Useful for |
* resource counting etc.. |
*/ |
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#define ATOMIC_INIT(i) { (i) } |
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/** |
* atomic_read - read atomic variable |
* @v: pointer of type atomic_t |
* |
* Atomically reads the value of @v. |
*/ |
static inline int atomic_read(const atomic_t *v) |
{ |
return (*(volatile int *)&(v)->counter); |
} |
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/** |
* atomic_set - set atomic variable |
* @v: pointer of type atomic_t |
* @i: required value |
* |
* Atomically sets the value of @v to @i. |
*/ |
static inline void atomic_set(atomic_t *v, int i) |
{ |
v->counter = i; |
} |
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/** |
* atomic_add - add integer to atomic variable |
* @i: integer value to add |
* @v: pointer of type atomic_t |
* |
* Atomically adds @i to @v. |
*/ |
static inline void atomic_add(int i, atomic_t *v) |
{ |
asm volatile(LOCK_PREFIX "addl %1,%0" |
: "+m" (v->counter) |
: "ir" (i)); |
} |
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/** |
* atomic_sub - subtract integer from atomic variable |
* @i: integer value to subtract |
* @v: pointer of type atomic_t |
* |
* Atomically subtracts @i from @v. |
*/ |
static inline void atomic_sub(int i, atomic_t *v) |
{ |
asm volatile(LOCK_PREFIX "subl %1,%0" |
: "+m" (v->counter) |
: "ir" (i)); |
} |
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/** |
* atomic_sub_and_test - subtract value from variable and test result |
* @i: integer value to subtract |
* @v: pointer of type atomic_t |
* |
* Atomically subtracts @i from @v and returns |
* true if the result is zero, or false for all |
* other cases. |
*/ |
static inline int atomic_sub_and_test(int i, atomic_t *v) |
{ |
unsigned char c; |
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asm volatile(LOCK_PREFIX "subl %2,%0; sete %1" |
: "+m" (v->counter), "=qm" (c) |
: "ir" (i) : "memory"); |
return c; |
} |
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/** |
* atomic_inc - increment atomic variable |
* @v: pointer of type atomic_t |
* |
* Atomically increments @v by 1. |
*/ |
static inline void atomic_inc(atomic_t *v) |
{ |
asm volatile(LOCK_PREFIX "incl %0" |
: "+m" (v->counter)); |
} |
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/** |
* atomic_dec - decrement atomic variable |
* @v: pointer of type atomic_t |
* |
* Atomically decrements @v by 1. |
*/ |
static inline void atomic_dec(atomic_t *v) |
{ |
asm volatile(LOCK_PREFIX "decl %0" |
: "+m" (v->counter)); |
} |
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/** |
* atomic_dec_and_test - decrement and test |
* @v: pointer of type atomic_t |
* |
* Atomically decrements @v by 1 and |
* returns true if the result is 0, or false for all other |
* cases. |
*/ |
static inline int atomic_dec_and_test(atomic_t *v) |
{ |
unsigned char c; |
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asm volatile(LOCK_PREFIX "decl %0; sete %1" |
: "+m" (v->counter), "=qm" (c) |
: : "memory"); |
return c != 0; |
} |
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/** |
* atomic_inc_and_test - increment and test |
* @v: pointer of type atomic_t |
* |
* Atomically increments @v by 1 |
* and returns true if the result is zero, or false for all |
* other cases. |
*/ |
static inline int atomic_inc_and_test(atomic_t *v) |
{ |
unsigned char c; |
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asm volatile(LOCK_PREFIX "incl %0; sete %1" |
: "+m" (v->counter), "=qm" (c) |
: : "memory"); |
return c != 0; |
} |
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/** |
* atomic_add_negative - add and test if negative |
* @i: integer value to add |
* @v: pointer of type atomic_t |
* |
* Atomically adds @i to @v and returns true |
* if the result is negative, or false when |
* result is greater than or equal to zero. |
*/ |
static inline int atomic_add_negative(int i, atomic_t *v) |
{ |
unsigned char c; |
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asm volatile(LOCK_PREFIX "addl %2,%0; sets %1" |
: "+m" (v->counter), "=qm" (c) |
: "ir" (i) : "memory"); |
return c; |
} |
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/** |
* atomic_add_return - add integer and return |
* @i: integer value to add |
* @v: pointer of type atomic_t |
* |
* Atomically adds @i to @v and returns @i + @v |
*/ |
static inline int atomic_add_return(int i, atomic_t *v) |
{ |
int __i; |
#ifdef CONFIG_M386 |
unsigned long flags; |
if (unlikely(boot_cpu_data.x86 <= 3)) |
goto no_xadd; |
#ifdef CONFIG_X86_32 |
# include "atomic_32.h" |
#else |
# include "atomic_64.h" |
#endif |
/* Modern 486+ processor */ |
__i = i; |
asm volatile(LOCK_PREFIX "xaddl %0, %1" |
: "+r" (i), "+m" (v->counter) |
: : "memory"); |
return i + __i; |
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#ifdef CONFIG_M386 |
no_xadd: /* Legacy 386 processor */ |
raw_local_irq_save(flags); |
__i = atomic_read(v); |
atomic_set(v, i + __i); |
raw_local_irq_restore(flags); |
return i + __i; |
#endif |
} |
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/** |
* atomic_sub_return - subtract integer and return |
* @v: pointer of type atomic_t |
* @i: integer value to subtract |
* |
* Atomically subtracts @i from @v and returns @v - @i |
*/ |
static inline int atomic_sub_return(int i, atomic_t *v) |
{ |
return atomic_add_return(-i, v); |
} |
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#define atomic_inc_return(v) (atomic_add_return(1, v)) |
#define atomic_dec_return(v) (atomic_sub_return(1, v)) |
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static inline int atomic_cmpxchg(atomic_t *v, int old, int new) |
{ |
return cmpxchg(&v->counter, old, new); |
} |
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static inline int atomic_xchg(atomic_t *v, int new) |
{ |
return xchg(&v->counter, new); |
} |
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/** |
* atomic_add_unless - add unless the number is already a given value |
* @v: pointer of type atomic_t |
* @a: the amount to add to v... |
* @u: ...unless v is equal to u. |
* |
* Atomically adds @a to @v, so long as @v was not already @u. |
* Returns non-zero if @v was not @u, and zero otherwise. |
*/ |
static inline int atomic_add_unless(atomic_t *v, int a, int u) |
{ |
int c, old; |
c = atomic_read(v); |
for (;;) { |
if (unlikely(c == (u))) |
break; |
old = atomic_cmpxchg((v), c, c + (a)); |
if (likely(old == c)) |
break; |
c = old; |
} |
return c != (u); |
} |
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#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0) |
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/* |
* atomic_dec_if_positive - decrement by 1 if old value positive |
* @v: pointer of type atomic_t |
* |
* The function returns the old value of *v minus 1, even if |
* the atomic variable, v, was not decremented. |
*/ |
static inline int atomic_dec_if_positive(atomic_t *v) |
{ |
int c, old, dec; |
c = atomic_read(v); |
for (;;) { |
dec = c - 1; |
if (unlikely(dec < 0)) |
break; |
old = atomic_cmpxchg((v), c, dec); |
if (likely(old == c)) |
break; |
c = old; |
} |
return dec; |
} |
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/** |
* atomic_inc_short - increment of a short integer |
* @v: pointer to type int |
* |
* Atomically adds 1 to @v |
* Returns the new value of @u |
*/ |
static inline short int atomic_inc_short(short int *v) |
{ |
asm(LOCK_PREFIX "addw $1, %0" : "+m" (*v)); |
return *v; |
} |
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#ifdef CONFIG_X86_64 |
/** |
* atomic_or_long - OR of two long integers |
* @v1: pointer to type unsigned long |
* @v2: pointer to type unsigned long |
* |
* Atomically ORs @v1 and @v2 |
* Returns the result of the OR |
*/ |
static inline void atomic_or_long(unsigned long *v1, unsigned long v2) |
{ |
asm(LOCK_PREFIX "orq %1, %0" : "+m" (*v1) : "r" (v2)); |
} |
#endif |
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/* These are x86-specific, used by some header files */ |
#define atomic_clear_mask(mask, addr) \ |
asm volatile(LOCK_PREFIX "andl %0,%1" \ |
: : "r" (~(mask)), "m" (*(addr)) : "memory") |
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#define atomic_set_mask(mask, addr) \ |
asm volatile(LOCK_PREFIX "orl %0,%1" \ |
: : "r" ((unsigned)(mask)), "m" (*(addr)) \ |
: "memory") |
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/* Atomic operations are already serializing on x86 */ |
#define smp_mb__before_atomic_dec() barrier() |
#define smp_mb__after_atomic_dec() barrier() |
#define smp_mb__before_atomic_inc() barrier() |
#define smp_mb__after_atomic_inc() barrier() |
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//#include <asm-generic/atomic-long.h> |
#endif /* _ASM_X86_ATOMIC_H */ |